Hylaeus pectoralis

Tilcayo Cats original · British Bees · Sources and editorial assessment · Originals retention rule

Hylaeus pectoralis is a solitary reedbed bee. In Britain it usually nests in empty galls: swellings on common reed made by the fly Lipara lucens. The bee uses the chamber after the fly leaves.

Identity

The species belongs to the family Colletidae and was described by Förster in 1871. Older names include Hylaeus kriechbaumeri and Prosopis palustris.

Identification depends on small structural features as well as colour. Alan Stubbs's 2007 test key distinguishes females by a combination including a black collar behind the head, a small strip of white hair at each side of the first abdominal segment and a substantial yellow area at the base of the hind tibia. The key is explicitly provisional and cautions against using it alone for a definitive identification.

British records and habitat

The species was long associated with the East Anglian fens. BWARS records a wider southern English distribution, including coastal sites, and describes its habitat as reedbeds beside both fresh and brackish water, sometimes extending into their drier margins. The Essex Field Club's account records it from Canvey Wick and lists it as threatened within Essex. That is a county designation, not a statement of its global extinction risk.

Life cycle

British adults are recorded from June to late September, in a single annual generation. Inside a reed gall the female builds a row of roughly one to eight brood cells. A glandular secretion dries into a thin lining around each cell. The completed nest is closed with finely divided leaf material; dry reed stems are occasionally used instead of galls.

Recorded flower visits include bramble, angelica, hogweed and wild carrot. The wasps Gasteruption assectator and G. jaculator have been reared from British nests of this bee.